| 1. |
- Baumeister, Hannah, et al.
(författare)
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A generalizable data-driven model of atrophy heterogeneity and progression in memory clinic settings
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Ingår i: Brain : a journal of neurology. - 1460-2156. ; 147:7, s. 2400-2413
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Tidskriftsartikel (refereegranskat)abstract
- Memory clinic patients are a heterogeneous population representing various aetiologies of pathological aging. It is unknown if divergent spatiotemporal progression patterns of brain atrophy, as previously described in Alzheimer's disease (AD) patients, are prevalent and clinically meaningful in this group of older adults. To uncover distinct atrophy subtypes, we applied the Subtype and Stage Inference (SuStaIn) algorithm to baseline structural MRI data from 813 participants enrolled in the DELCODE cohort (mean ± SD age = 70.67 ± 6.07 years, 52% females). Participants were cognitively unimpaired (CU; n = 285) or fulfilled diagnostic criteria for subjective cognitive decline (SCD; n = 342), mild cognitive impairment (MCI; n = 118), or dementia of the Alzheimer's type (n = 68). Atrophy subtypes were compared in baseline demographics, fluid AD biomarker levels, the Preclinical Alzheimer Cognitive Composite (PACC-5), as well as episodic memory and executive functioning. PACC-5 trajectories over up to 240 weeks were examined. To test if baseline atrophy subtype and stage predicted clinical trajectories before manifest cognitive impairment, we analysed PACC-5 trajectories and MCI conversion rates of CU and SCD participants. Limbic-predominant and hippocampal-sparing atrophy subtypes were identified. Limbic-predominant atrophy first affected the medial temporal lobes, followed by further temporal and, finally, the remaining cortical regions. At baseline, this subtype was related to older age, more pathological AD biomarker levels, APOE ε4 carriership, and an amnestic cognitive impairment. Hippocampal-sparing atrophy initially occurred outside the temporal lobe with the medial temporal lobe spared up to advanced atrophy stages. This atrophy pattern also affected individuals with positive AD biomarkers and was associated with more generalised cognitive impairment. Limbic-predominant atrophy, in all and in only unimpaired participants, was linked to more negative longitudinal PACC-5 slopes than observed in participants without or with hippocampal-sparing atrophy and increased the risk of MCI conversion. SuStaIn modelling was repeated in a sample from the Swedish BioFINDER-2 cohort. Highly similar atrophy progression patterns and associated cognitive profiles were identified. Cross-cohort model generalizability, both on the subject and group level, were excellent, indicating reliable performance in previously unseen data. The proposed model is a promising tool for capturing heterogeneity among older adults at early at-risk states for AD in applied settings. The implementation of atrophy subtype- and stage-specific end-points may increase the statistical power of pharmacological trials targeting early AD.
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| 2. |
- Holmquist, Lars Erik, et al.
(författare)
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Building Intelligent Environments with Smart-Its
- 2004
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Ingår i: IEEE Computer Graphics and Applications. - 0272-1716 .- 1558-1756. ; 24:1, s. 56-64
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Tidskriftsartikel (refereegranskat)abstract
- The development of Smart-Its for building smart environments is discussed. Smart-Its are small, self-contained, stick-on computers that attach to everyday objects. These augmented objects become soft media, enabling dynamic digital relationships with users and each other. A Smart-Its consists of a core board with a wireless transceiver to let the device communicate with other Smart-Its, plus a sensor board that gives the Smart-Its data about its sorroundings. The major advantage of the system is that it allows designers and researchers to construct responsive or intelligent environments.
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| 3. |
- Van Laerhoven, K., et al.
(författare)
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Pin and play : The surface as network medium
- 2003
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Ingår i: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 41:4, s. 90-95
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Tidskriftsartikel (refereegranskat)abstract
- Integrating appliances in the home through a wired network often proves to he impractical: routing cables is usually difficult, changing the network structure afterward even more so, and portable devices can only be connected at fixed connection points. Wireless networks aren't the answer either: batteries have to be regularly replaced or changed, and what they add to the device's size and weight might be disproportionate for smaller appliances. In Pin&Play, we explore a design space in between typical wired and wireless networks, investigating the use of surfaces to network objects that are attached to it. This article gives an overview of the network model, and describes functioning prototypes that were built as a proof of concept.
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